How to Spot a Hidden Water Leak Before It Gets Expensive

A dripping faucet is annoying but obvious. The leaks that do real damage are the hidden ones — inside walls, under slabs, in yards. By the time they're visible, they've often been running for weeks. Here's how to catch them early.

Watch your water bill

An unexplained jump in your water bill is often the first sign of a hidden leak. If your usage habits haven't changed but the bill has, something somewhere is running.

Try the meter test

Turn off every faucet and water-using appliance in the house, then check your water meter. If the flow indicator is still moving, water is going somewhere it shouldn't be. This simple test confirms a leak exists — finding it is the next step.

Know the other warning signs

• The sound of running or hissing water when everything is off
• Warm or damp spots on floors, especially over a slab
• Musty odors or unexplained mold or mildew
• Staining, bubbling paint, or soft spots on walls and ceilings
• Soggy or unusually green patches in the yard
• Cracks in flooring or foundation

Don't guess — locate it

Professional leak detection uses listening equipment, pressure testing, and cameras to pinpoint a leak without tearing into walls or floors on a hunch. If any of these signs sound familiar, it's worth having the leak found precisely before it finds you.